President Donald Trump says he will designate Antifa as a "major terrorist organization" and threatened to investigate the organization's funders, according to a post on Truth Social.

"I am pleased to inform our many U.S.A. Patriots that I am designating ANTIFA, A SICK, DANGEROUS, RADICAL LEFT DISASTER, AS A MAJOR TERRORIST ORGANIZATION," Trump wrote. "I will also be strongly recommending that those funding ANTIFA be thoroughly investigated in accordance with the highest legal standards and practices."

Trump's comments come a week after conservative activist Charlie Kirk was killed on a Utah university campus while giving a speech. Trump and other administration officials quickly blamed Kirk's death on radical leftwing groups like Antifa, although investigators have not offered any direct evidence that the shooter was affiliated with those groups.